1. Field of the Invention
The present invention relates to projector devices, such as liquid crystal projectors, for projecting an image-forming beam on a screen using a lamp as a light source.
2. Description of the Related Art
Projector devices of the type mentioned comprise as arranged in a casing a lamp unit, and an optical system including a polarization beam splitter, polarizing plates, liquid crystal panels, a projection lens, etc. The lamp unit has a mercury lamp disposed within a housing and an exhaust fan disposed to the rear of the mercury lamp. Air streams are produced around the mercury lamp by operating the exhaust fan for cooling the lamp.
However, with high-luminance projector devices wherein a superhigh-pressure mercury lamp is used as the light source, the mercury lamp generates a large quantity of heat and therefore requires high-speed rotation of the exhaust fan to produce air streams at a high speed and fully cool the lamp. This entails the problem that the exhaust fan makes a great noise.
An object of the present invention is to provide a projector device wherein the light-source lamp can be effectively cooled with reduced quantities of air streams.